A coaxial connector has an engineering attribute known as a characteristic impedance. The characteristic impedance is a quantified value from which can be determined the amount of propagation delay that the connector will impart to an electrical signal of a given frequency. A desired characteristic impedance should be matched as closely as practicable throughout the length of the coaxial connector along which the electrical signal propagates.
A construction of a coaxial connector that provides impedance compensation, refers to an intentional construction of the connector that compensates for an undesired impedance mismatch due to insulation materials with different dielectric constants in the radial or diametric space between the contact and the concentric shell, and due to a change in the diametric dimension separating the contact and the concentric shell.
A coaxial connector disclosed in U.S. Pat. No. 3,366,920, is constructed with impedance compensation. Portholes are provided in the connector through which a tool enters to apply crimping forces. The portholes provide air gaps for atmospheric air that has a different dielectric constant than those of solid dielectric materials used to construct the connector. Impedance compensation is provided, after the crimping forces have been applied, by assembling a bushing having insulative ribs that extend into the portholes to replace atmospheric air with solid dielectric material.
A coaxial connector known from U.S. Pat. No. 3,757,278, comprises, a conductive electrical contact for connection with a signal conductor of an electrical cable, a conductive shell concentrically encircling the contact for connection with a conductive shield of the cable, and insulation concentrically between the contact and the shell. The contact is assembled by movement into a rear of the shell, and registers against a rear of a dielectric sleeve, and thereby is restrained from movement.